NBC published the results of a new national poll on July 21. In this poll, which was commissioned by NBC News, respondents were asked for whom they would vote if Hillary Clinton were the Democratic Party's candidate and Donald Trump were the Republican Party's candidate.
NBC poll results
Of those who responded, 46.0% said that they will vote for former Secretary of State Hillary Clinton, while 45.0% declared that they would give their vote to billionaire Donald Trump.
The poll was conducted from July 11 to July 17 via Internet. A total of 2002 participants responded. There is a sampling error of +/-1.0 percentage point. Considering this error margin, the race is currently a statistical tie.
Putting the results in context
Single polls should be regarded with caution, as they may contain large errors. Rather, one should examine how a poll's results compare to benchmark forecasts.
For the following comparison, we convert the candidates' raw poll numbers into shares of the two-party vote. This yields figures of 50.6% for Clinton and 49.5% for Trump. On July 18 Clinton received 52.9% in the NBC poll and Trump received only 47.1%.
Results compared to other polls
Clinton currently achieves 52.0% of the major two-party vote according to an average of recent polls. This value is 1.4 percentage points higher than her corresponding numbers in the NBC poll. This difference is outside the poll's margin of error, which means that the poll is an outlier.
The poll compared with PollyVote's forecast
The current PollyVote foresees Clinton to gain 52.4% of the two-party vote. Hence, Polly's prediction is 1.8 points above her polling numbers. Again, a look at the poll's error margin reveals that this deviation is significant.